I don't know. I mean, 5e's default method is rolling, and most people seem to prefer point-buy. I don't think it's possible to find a consensus on how many people used Method I, but given the high stats most characters I saw had, I'm pretty sure it wasn't all that popular, lol.
One thing you keep saying about 2e is all these books were optional, thus preventing a CharOp mindset from coming into play. But so were all the 3e books! No DM was forced to use Magic of Arcanum, Tome of Battle, or Complete Adventurer, just as no DM was forced to use The Complete Sha'ir's Handbook or any Dragon Magazine content.
The main difference, as I see it, between the community that built up around the two editions was not only the internet, but the mindset of the role of the player and the DM.
In 2e, the DM was still considered the absolute authority, who no doubt had reams of house rules, and their own curated list of what was "kosher" for their tables.
In the year 2000, you had a lot of new players and a lot of old players who now had a forum to share their stories of DM power gone horribly wrong, and this mindset of "trust the rules, not the DM" began to appear, where in the TSR era, you couldn't trust the rules because there was simply too much vagueness that required a DM to sort out.
Random Example: The Complete Book of Humanoids doesn't allow Centaurs to be Priests, but Monster Mythology has a writeup for specialty Priests of Skerrit, the God of Centaurs. Paging the DM!
With all the effort put into balancing the game, surely what WotC was giving us could be trusted! Nothing is wrong with any of their player options! Surely if you gave players assumed wealth and magic items and used the CR system, nothing could go wrong!
Ah, how innocent we were. But it was an attractive illusion, since you could aim the rulebooks at stingy, recalcitrant DM's and tell them they were doing it wrong, a far cry from Gary's rants that if you were to give players a fair shake, they would utterly destroy your game world!
And of course, by the time we knew better, we were invested in the system, and, thanks to the OGL, the system was everywhere even if you wanted to change games, lol!
Sure, WotC eventually fessed up, but their solution to that was to sell us more books! Who didn't love getting errata to Polymorph in Complete Arcane or rebalanced magic items in the Magic Item Compendium? And of course, things like the Tome of Battle broke the community in half "wut, you mean martials are supposed to be good? Blasphemy!".
But I digress. Optimization was certainly there (anyone who has played Pool of Radiance or Baldur's Gate I knows), but there was a limit on what the DM would put up with, and it wasn't like most people had a plethora of other groups they could play with. Plus, people who scoured rulebooks for cool new options were NERDS, amirite?